探讨了城市污水SNAD生物膜反应器在高溶解氧工况下的脱氮性能. SBR反应器以城市生活污水为进水,反应器内放置鲍尔环生物膜载体,控制温度为30℃,采用间歇曝气方式,曝气阶段曝气量为500L/h,溶解氧浓度达5mg/L.阶段1控制曝气和非曝气时间都为20min,生物膜的NOB活性较低,反应器具有良好的脱氮性能.反应器的总氮平均去除率和出水总氮浓度平均值分别为89%和11mg/L.阶段2、阶段3和阶段4研究了曝气时间对反应器脱氮性能的影响.曝气时间对生物膜的厌氧氨氧化活性影响较小,对生物膜的NOB活性影响较大.阶段3控制曝气时间为60min,生物膜的NOB活性较低,反应器的总氮平均去除率和出水总氮浓度平均值分别为83%和14mg/L.阶段4控制曝气时间为160min,生物膜的NOB活性较高,反应器的总氮平均去除率降低至50%,出水总氮浓度平均值为35mg/L.%The simultaneous partial nitrification, anammox and denitrification (SNAD) process for treating domestic wastewater was investigated under high dissolved oxygen (DO) concentration. Intermittent aerobic condition was operated in a sequencing batch reactor (SBR) with the air flow rate of 500L/h at 30℃. The DO concentration was up to 5mg/L. Domestic wastewater was used as influent and Kaldnes rings were used as biomass carriers. In phase 1, the reactor was operated with the aerobic time and non-aerobic time of both 20min. As a result, the biofilm performed low nitrite oxidizing bacteria (NOB) activity and the reactor achieved high nitrogen removal performance. The average total inorganic nitrogen (TIN) removal efficiency reached 89% with the average effluent TIN concentration of 11mg/L. Besides, the effect of the aerobic time on the SNAD biofilm reactor performance was evaluated during phase 2, phase 3 and phase 4. The results showed that the length of aerobic time played a little effect on the anammox activity of the SNAD biofilm, while the NOB activity was largely affected by the length of aerobic time. In phase 3, the aerobic time was controlled at 60min. As a result, the biofilm performed low NOB activity and the reactor achieved high nitrogen removal performance. The average TIN removal efficiency reached 83% with the average effluent TIN concentration of 14mg/L. The aerobic time of phase 4was controlled at 160min. On the contrary, the biofilm performed high NOB activity and the reactor performed poor nitrogen removal performance. The average TIN removal efficiency decreased to 50% with the average effluent TIN concentration of 35mg/L.
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